To determine the clinical characteristics predicting the onset of visual hallucinations (VHs) in Parkinson’s disease (PD) in clinical practice.

VHs are common symptoms and are associated with reduced quality of life. However, it remains challenging to predict the onset of VHs.

This study includes 107 PD patients admitted to our institution. We retrospectively investigated clinical information including age at onset, initial symptoms, time from onset to each Hoehn and Yahr (H&Y) stage, and the onset of VHs. We defined the rate of motor decline in each patient by calculating the slope of the approximate line of annual H&Y stage change and analyzed the correlation with the time of VHs onset.

In our cohort, 75% of patients (80/107) developed VHs (48 female and 32 male). The mean age at PD onset was not significantly different (69 ± 9 in non-VHs patients and 65 ± 10 patients in VHs patients). There were significantly more patients with tremor as an initial symptom in the VHs group than in the non-VHs group (P = 0.0374). In VHs patients, the mean time from PD onset to VHs onset was 9 ± 5 years. The decline rate of H&Y scale was negatively correlated with the time from PD onset to VHs onset (P < 0.0001); PD patients with the rapid progress of H&Y scale developed VHs significantly earlier.